[Table Visualization][BUG] partical rows shows metrics for all columns (

#2648)

Currently, when we enable Show partial rows in the Options panel, we see metrics been
added to every column even though Show metrics for every bucket/level is not enabled.

Metrics are added and returned when we enable the partial rows. This PR fixed the bug
by slice the returned data to allow only the last set of metrices.

Partially resolved:
#2579 (comment)

Signed-off-by: Anan Zhuang <ananzh@amazon.com>

src/plugins/vis_type_table/public/to_ast.ts

@@ -21,10 +21,15 @@ export const toExpressionAst = (vis: Vis, params: any) => {
   );
 
   const schemas = getVisSchemas(vis, params);
+  // manul slice to remove duplicate metrics
+  const metrics =
+    schemas.bucket && vis.params.showPartialRows && !vis.params.showMetricsAtAllLevels
+      ? schemas.metric.slice(-1 * (schemas.metric.length / schemas.bucket.length))
+      : schemas.metric;
 
   const tableData = {
     title: vis.title,
-    metrics: schemas.metric,
+    metrics,
     buckets: schemas.bucket || [],
     splitRow: schemas.split_row,
     splitColumn: schemas.split_column,